[SEM study and clinical observations of "Turner teeth"].

The altered structure of "Turner-teeth" was examined under the scanning electron microscope. The enamel surface revealed developmental disorders such as bowl-shaped pits, Tomes' process pits and enamel craters with rounded borders. On the fractured surfaces of yellowish discolored enamel, localized islands of pathological enamel were found. The enamel rods were atypically arranged and poorly mineralized. Surprisingly the prisms formed later by the same ameloblast often exhibited a entirely normal structure.